An investigation of the conductivity of peptidenanotube networks prepared by enzyme-triggered self-assembly

Abstract

We demonstrate that nanotubular networks formed by enzyme-triggered self-assembly of Fmoc-L₃ (9-fluorenylmethoxycarbonyl-tri-leucine) show significant charge transport. FT-IR, fluorescence spectroscopy and wide angle X-ray scattering (WAXS) data confirm formation of β-sheets that are locked together via π-stacking interactions. Molecular dynamics simulations confirmed the π–π stacking distance between fluorenyl groups to be 3.6–3.8 Å. Impedance spectroscopy demonstrated that the nanotubular xerogel networks possess minimum sheet resistances of 0.1 MΩ/sq in air and 500 MΩ/sq in vacuum (pressure: 1.03 mbar) at room temperature, with the conductivity scaling linearly with the mass of peptide in the network. These materials may provide a platform to interface biological components with electronics.